Probably true but you would leave with a conviction of drug abuse.... why not simply put your notice in? A friend of mine who still had 3 years RoS to complete knocked on the CO's door with his resignation letter in one hand accompanied from a letter from his solicitor in the other hand. The solicitors letter was well constructed and essentially stated that the RoS was illegal and against his clients human rights and that he was prepared to take the MOD to court to prove that it was illegal.
Within 15 minutes (following swift phone call from CO to somone much higher) the young man was infomed that he would be released within the normal time scales (12 months notice) and that the MOD would waive their claim on any RoS.